The gas phase oxidation of alkanes and alkenes can lead to oxidation products which are more valuable then the starting compounds.
K. Aykan et al. in U.S. Pat. No. 3,843,553 issued Oct. 22, 1974 disclose catalyst compositions of Scheelite crystal structure containing bismuth ions, divalent ions and cation vacancies.
K. Aykan et al. in U.S. Pat. No. 3,806,470 issued Apr. 23, 1974 disclose catayst compositions of Scheelite crystal structure containing certain ions having ionic radii in the range of about 0.9 A to about 1.6 A.
Vanadium-phosphorous catalysts have been disclosed for the oxidation of butane to maleic anhydride in several references including E. Bondes et al., J. Catal., vol. 57, pp. 236 et. seq. (1979).
Addition of vanadium to an Sb-Mo-O system to produce a catalyst for propylene and isobutylene oxidation is disclosed in Chem. Abstr. 77:163919k.
These references are representative of the art with regard to heterogeneous catalyzation of hydrocarbon oxidation.
Zolotukhina et. al. disclose properties of Cr.sub.x Nb.sub.x V.sub.2-2x O.sub.4 and Fe.sub.x Nb.sub.x V.sub.2-2x O.sub.4 (O&lt;x&lt;0.09) solid solutions in articles abstracted at Chem. Abstr. 88:113568b, 88:129496n and 88:56771m.
In the rutile structure every metal atom is surrounded by six oxygen neighbors and each oxygen has three metal ion neighbors. Strings of edge sharing MO.sub.6 octahedra extend along one direction and are connected to adjacent strings by corner sharing.
The unit cell of the trirutile structure corresponds to three unit cells of the simple rutile structure wherein the metal positions are occupied in an ordered way by two pentavalent and one divalent metal ions or two trivalent and one hexavalent metal ions. The columbite structure is related to the trirutile structure in that the metal coordination remains octahedral and the metal atoms are ordered in an analogous manner. They differ, however, in that the strings of edge shared octahedra form a zig-zag pattern in the columbite structure and run in straight chains in the trirutile structure.